Indiana and other Midwestern corn and soybean farmers are being accused of threatening the survival of monarch butterflies.
Up to a billion monarchs formerly colored our skies each summer, yet only about 33 million remain — a decline of more than 90 percent since the mid-1990s, according to the Endangered Species Coalition.
"I've only seen two or three monarchs this year, which is following the pattern of fewer and fewer each year," Carolee Snyder of Carolee's Herb Farm in Blackford County told The Star Press. "And I hardly found any eggs or caterpillars on any of my milkweed plants even though I am planting more and more milkweed every year."
Snyder began growing herbs for teas in her backyard in the 1960s.
Gardeners, hikers, wildlife photographers, students, scientists, zoo veterinarians, biology teachers, Lutherans, Methodists, Presbyterians and other groups belonging to the coalition fear future generations of Americans will no longer see the butterfly.
The widespread use of the weed killer glyphosate, aka Roundup, is killing milkweed — on which the butterflies are totally dependent — across millions of acres of the monarch's summer habitat in the Corn Belt, the coalition says.
"The declining milkweed population is not the only reason for the decline in monarch butterflies," Jane Ade Stevens, CEO of Indiana Soybean Alliance and Indiana Corn Marketing Council, told The Star Press in a prepared statement. "When looking at this complex issue, you must also include the loss of forestland in the monarch's overwintering home in Mexico and extreme-weather temperature fluctuations in recent years that all contributed to the decline in the monarch population."
The coalition calls the large orange and black monarchs "symbols of summer-time outdoors" and "ambassadors of nature in people's backyards and gardens."
Millions of school children have reared monarchs in classrooms and learned about metamorphosis by watching the caterpillars transform. Monarchs have been reared on the international space station. They are the official state butterfly of no less than seven states.
"The factors that are causing monarch numbers to plummet also threaten many other species of butterflies and bees, which in turn threatens the well-being of people because the food security of humans is dependent on the ecological services that pollinators provide," the coalition says in a petition asking the federal government to list the monarch as a "threatened species."
If the petition is approved, the monarch would join a list of threatened species that includes polar bears, the American crocodile and the yellow-billed cuckoo bird.
Joe Russell, a local Farm Bureau leader who has been a grain farmer for four decades, told The Star Press, "The number one herbicide on the market, whatever it is, is always being attacked and blamed for everything."
He noted that all herbicides must be approved by the U.S. Environmental Protection Agency.
"I graduated from high school when they had the first Earth Day (in 1970)," Russell said. "Since then, we've improved the air, the water and the food quality, and they're still complaining like the end is near. If Roundup was causing the great demise of the tapeworm, I doubt that would be in the newspaper. But butterflies are something cute, cuddly and adorable."
Russell still sees monarchs and milkweed on roadsides, railroad rights of way, ditches, backyards and other sites. "So they'll have to give me more proof," he said.
Estimates of monarch populations east of the Rockies are based on overall abundance of monarchs that roost during the winter in the mountains of inland Mexico, according to the coalition. Scientists rely on the combined land area housing overwintering colonies for the estimates because it is a direct measure of the entire migratory population.
The coalition also cites studies showing that the drastic loss of milkweed is caused by increased and later-season use of glyphosate in conjunction with widespread planting of genetically engineered, glyphosate-resistant (aka "Roundup Ready") corn and soybeans in the Corn Belt.
Monarchs lay their eggs on milkweed. Caterpillars eat the leaf tissue and along leaf edges to grow, while using the plant's chemicals for their own defense against predators.
Between 1995 — the year before Monsanto introduced Roundup Ready soybeans and three years before it introduced Roundup Ready corn — and 2013, total glyphosate use on corn and soybeans rose from 10 million pounds per year to 204 million pounds per year. Roundup Ready varieties now comprise 94 percent of all soybeans and 89 percent of all corn grown in the United States.
More than 11,000 Indiana farmers are licensed pesticide applicators.
Philip T. Marshall, the state entomologist for Indiana, says residential, commercial and industrial sprawl also are contributing to the loss of milkweed, along with intense agricultural practices that remove fence rows.
"That impacts monarchs, but is also why people are seeing deer in cities now," Marshall said. "Places for wildlife away from cities are decreasing."
He believes it is possible that future generations will see fewer monarchs but added, "Nature changes and adapts. I never saw deer as a kid and only had to worry about deer crossing the highway when I went by a state park. Now I have to watch for deer in my subdivision which is on the edge of town. So I expect the monarchs to adapt. Plus, there are commercial butterfly farmers that sell monarchs and other butterflies for release."
The coalition says the capture, sale, transport and release of monarchs can threaten the butterfly's well-being because of disease transmission and loss of genetic diversity. Commercial monarchs can also interfere with studies of the distribution and movement of wild monarchs. In addition, harvesting wild monarchs has the potential to exacerbate population decline.
"A 90-percent decline in the last two decades in what was once a common species in our backyards is pretty dramatic," said entomologist Sarina Jepsen, endangered species director at the Xerces Society. "There are a lot of threats, but the primary one is the twenty-fold increase in the use of glyphosate since the mid-1990s, coincident with the onset of genetically modified corn and soybeans to tolerate the use of Roundup."
She cited a Canadian model that put the probability of monarch "quasi-extinction," meaning less than 1,000 monarchs, at 5 percent in the next 100 years.
"I like those odds," she said. "There's a 95 percent chance they won't go extinct, but this should be something to consider, a wake-up call, because we are chemically changing the landscape dramatically."